Answer:
F = - 1,598 10⁻³ N
Explanation:
Electic strength is given by Coulomb's law
F = k q₁ q₂ / r²
Where k is the Coulomb constant that is worth 8.99 10⁸ N m²/C², q₁ and q₂ are the charges and r is the distance that separates the electric charges
In this case the charge of the two spheres is the same and of a different sign since when you remove the charge of a sphere that was initially neutral, it is left with that charge removed but of the opposite sign
q₁ = q₂ = 2.50 10¹³ electrons = 2.50 10¹³ 1.6 10⁻¹⁹
q₀ = 4.0 10⁻⁶ C
Let's calculate
F = - 8.99 10⁸ (4.0 10⁻⁶)² / 0.30²
F = - 1,598 10⁻³ N
Answer:
A) Option 1 is the correct answer.
B) Option 4 is the correct answer.
Explanation:
A) Weight of liquid = 7 N
Volume of liquid = 1 L = 0.001 m³
Specific weight = 
Density = 
Specific gravity = 
Option 1 is the correct answer.
B) The Stokes(St) is the cgs physical unit for kinematic viscosity, named after George Gabriel Stokes.
We have
1 St = 10⁻⁴ m²/s
Option 4 is the correct answer.